In the electronics industry circuit miniaturization and more compact packaging arrangements have led to the development of different types of connectors for electrically connecting substrates. In general such connectors may be utilized to provide a detachable electrical connection between adjacent circuit boards. As an example, stacked connectors provide a connection for circuit boards that are stacked relative to one another.
Such connectors generally utilize spring contact elements to bridge the gap between the stacked substrates and electrically connect the individual conductors formed on the peripheral edges of each substrate. The spring contact elements may be molded to the connector and are typically mounted in channels formed on the connector. As an example, the connector may be clamped between the substrates by fixedly attaching the connector to both of the substrates using threaded fasteners or the like. U.S. Pat. No. 4,057,311 to Evans and U.S. Pat. No. 3,551,750 to Sterling disclose representative prior art connectors and mounting arrangements for stacked substrates.
Another mounting arrangement for stacked substrates uses surface compression generated between the substrates to sandwich the connector therebetween. In this case the connector may be attached to one of the substrates and is compressed between the substrates. The substrates may be mounted to a separate holder or frame that holds the substrates in a parallel spaced alignment.
With any connector it is of primary importance to maintain electrical contact between the individual contacts of the connector and the individual conductors of the stacked substrates. Since with most stacking arrangements the connector is typically fixedly attached to one of the substrates, any variations between the spacing of the substrates must be bridged by deflection of the spring contacts. Such variations in the spacing between substrates may occur for example, due to accumulated tolerances, board deflections or variations in board thickness.
A spring contact of a connector may not contain enough travel, however, to maintain electrical contact if the spacing at any point between the stacked substrates is too large. Moreover, with conventional connectors it may be difficult to form the spring contacts with a large amount of deflection to accommodate an accumulation of tolerances.
The present invention is directed to an electrical connector in which the connector is free to move or "float" relative to the separate stacked substrates. This in effect maximizes the effective contact height on at least one side of the connector.
It is therefore an object of the present invention to provide an electrical connector for stacked substrates that is free to move or float between the substrates to enable increased contact efficiency. It is a further object of the present invention to provide an electrical connector that maximizes the effective contact height of the spring contacts on at least one side of the connector to compensate for large or irregular spacing between stacked substrates. It is yet another object of the present invention to provide an electrical connector that is simple to use, relatively easy to manufacture, and comparatively cost-effective.